1. Field of the Invention
The present invention relates to a conductive film, a display device having the same, and a method of evaluating the conductive film. Specifically, the present invention relates to a conductive film that has a random mesh-shaped wiring pattern capable of providing image quality which is improved in terms of visibility of moiré in accordance with an emission intensity of a display device even if the pattern overlaps with pixel array patterns of the display device having different emission intensities, a display device having the same, and a method of evaluating the conductive film. It should be noted that, in the present invention, the visibility of moiré indicates a degree to which moiré is not visually perceived or a degree to which it is difficult for moiré to be visually perceived. In addition, improvement or advancement in terms of the visibility of moiré means that it becomes difficult for moiré to be visually perceived or that moiré does not become visually perceived.
2. Description of the Related Art
Examples of conductive films, each of which is provided on a display unit of a display device (hereinafter referred to as a display), include a conductive film for a touch panel having a conductive layer formed of thin metal lines which have a mesh-shaped wiring pattern (hereinafter referred to as a mesh pattern), a conductive film for an electromagnetic shield, and the like.
Regarding such conductive films, since there is a problem that a moiré caused by interference between a mesh pattern and a pixel array pattern (for example referred to as an array pattern of RGB color filters or a black matrix (hereinafter also referred to as a BM) pattern as a reverse pattern thereof) of a display may be visually perceived, various conductive films having a mesh pattern due to which a moiré is not visually perceived or unlikely to be visually perceived have been proposed (for example, refer to JP2013-214545A).
In a technology disclosed in JP2013-214545A according to the present application of the applicants, a rhomboid shape of a mesh pattern, which allows the sum of intensities of moirés within a predetermined frequency range in which the frequency of moiré is determined depending on visual response characteristics to be equal to or less than a predetermined value, is made to be irregular in accordance with widths of thin metal lines constituting the mesh pattern, with respect to frequencies and intensities of moirés obtained by applying human visual response characteristics to frequency information and intensity information of moirés respectively calculated from peak frequencies and peak intensities of respective spectrum peaks of a two-dimensional Fourier (2DFFT) spectrum of transmittance image data of a rhomboid (diamond) mesh pattern of the conductive film and a two-dimensional Fourier (2DFFT) spectrum of transmittance image data of a pixel array (BM) pattern of the display. As a result, it is possible to suppress occurrence of moiré, and it is possible to improve visibility.